By default, a surface's axis is at the centre of the surface. Use the Surface Offset X and Y fields to offset a surface along the X-axis or Y-axis. All rotations, scaling, and shearing applied to a surface are applied about its axis. The location of the axis is indicated by the axis icon in the scene.
To offset a surface:
- Select the surface you want to offset.
- In the Surface menu, change the Surface Offset X and Surface Offset Y fields accordingly.
(a) Surface Offset fields
The following figure illustrates the difference between rotating a surface that has not been offset and a surface offset using the Surface Offset X field.
Rotated image with no offset. Notice that the axis is in the centre of the image.
Rotated image with an offset along the X-axis. Notice that the axis is offset from the image centre.